1. Field of the Invention
The present invention relates to an auto-focus camera, and more particularly to an auto-focus camera which has a manual focus mode for a manual focusing and an auto-focus mode for an automatic focusing, and which has an AF lock function holding a focusing value for focusing by an auto-focus (AF) mechanism in the auto-focus mode and an AE lock function holding a photometry value for controlling an automatic exposure (AE) mechanism.
2. Description of the Related Art
The conventional camera is provided with an AF lock function and an AE lock function for preparing for the photographing when the shutter button is half depressed, and for performing the photographing when the shutter button is depressed completely. That is, when the shutter button is half depressed, a subject distance is measured by an auto-focus (AF) function, and a focusing is performed based on the result (a focusing value). A subject brightness is measured by an automatic exposure (AE) function, and a stop value and a shutter speed are set based on the result (a photometry value) (exposure setting). When the shutter button is depressed completely, the stop value and the shutter speed are controlled (exposure control), so that the shutter can be released. In the above-described camera, the focusing value and the photometry value when the shutter button is half depressed are held (AF lock and AE lock) while the shutter button is being half depressed. For example, if the photographing is performed in such a state that the focus point and the exposure are adjusted to a subject outside a focus area, the following processes are executed.
First, a photographing direction of the camera is directed to a subject, which is desired to be focused. Then the shutter button is half depressed, and the focus point is set to the subject. The camera is turned in a desired photographing direction while the shutter button is being half depressed, and then the shutter button is depressed completely. As a result, the photographing can be performed in such a state that the focus point and the exposure are set to the subject outside the focus area.
However, if the photographing is performed in such a state that the subject outside the focus area is focused as mentioned above, the exposure is adjusted to the subject outside the focus area. Therefore, there is a disadvantage in that the exposure is not correct if the subject brightness in photographing is different from the subject brightness in focusing.
Moreover, in the sequential photographing in the auto-focus mode, the focusing is performed every time the shutter button is half depressed. So, there is a disadvantage in that it takes much time until the shutter is released; therefore, the perfect moment for a good picture is missed. The subject distance hardly changes in the case of the sequential photographing. So, a camera, which can selectively fix a focus point once the focusing is performed, and control the exposure only so that the shutter speed can be faster, is desired.
Furthermore, as the functions of the camera increase, the set items of the photographing conditions increase. It is difficult to provide a switch, which sets the photographing conditions, in a limited space in a camera. Thus, it is hoped that one switch is used for setting the photographing conditions, so that the number of switches can be reduced.